1. Field of the Invention
The present invention relates to mud or suitable liquid motor systems. More particularly, the present invention relates to an improved system for a mud motor which incorporates fluid bearings within the system, and eliminates leakage of fluid within the system through a unique sealing assembly.
2. General Background
The utilization of a mud driven motor for rotating a drill or other specialty bit in the process of drilling oil or workover wells is well known. The system would normally include a rotor assembly housed within an exterior stator, with the rotor coupled to the upper end of a drive shaft, several upper and lower output shafts engaged to a drill bit. Mud is run through the stator/rotor assembly, which causes the rotor to rotate, which in turn provides rotation to the drill bit. The mud is recycled to the surface, where, after undergoing treatment is recirculated though the mud motor system downhole.
Of course, when drive or output shafts are housed within an exterior casing or stator assembly, the rotation of the shafts generate friction and wear. To prevent this detrimental effect, the internal spaces between the shaft and its housing are usually provided with a lubricating fluid, which is effectively sealed within the space so that the wear of the shaft is reduced by the lubricant. Or, a certain amount of mud is allowed to "leak" through the bearings. Of course, the lubricating fluid must be maintained within a sealed area, since it cannot mix with the mud driving the motor (if it is the sealed bearing design of motor).
However, oftentimes, during the drilling process utilizing a mud motor system, the thrust produced on the formation results in a certain amount of vibration and other movement of the shafts within the motor casings. This side-to-side movement of the shafts creates an instantaneous and minute gap between the sealing members around the shaft and the shaft seal diameter. The result is usually the seepage of the lubricating oil out of the system, and movement of the oil into the mud system, or worse yet, loss of sufficient oil due to leakage, that the shaft is rotating within its housing with no or little lubrication which could result in excessive wear or seizure of the motor.
A second problem encountered in the mud motor systems utilized today is the amount of damage (short life) that these systems undergo due to insufficient thrust bearing assemblies in the systems. The common metal-to-metal or metal-to-rubber bearing systems result in a great amount of wear during drilling, and lend to the leakage problem heretofore discussed. When, of course, the bearings wear, they must be changed, or the result could be loss of the entire system. This is time-consuming and expensive.
There have been several patents noted in applicant's prior art statement provided herewith which address the general subject matter of mud motor systems, but fail to correct the problems as cited.